Core catcher



April-1.3,. 1.937- G. F( GRIMMELSMAN A' ,2,675,837 'Y GORE CATCHER -l4, A' v/4/ A April 13, 1937. G. F. GRIMMELSMAN 2,076,837

" l GORE CATCHER Filed Feb. i5,- 1956 v 2 sheets-sheet 2 32 30 39 .55. 'E 5 4/ a 33 a a7- Patented Api. l13, 1 937 PATENT OFFICE conn carolina George F. Grimmelsman, Los Angeles, Calif., as-

signor to Globe Oil Tools Company, Los Nietos, Calif., a corporation of California Application February 15 1-7fClaims.

This invention relates toa well tool and relates 4 more particularly to a core catcher for use in a core catcher embodying core gripping slips ping slips carried by spring 'fingers and the core that cannot foul the core. core catcher now in general use embodies gripentering lthe drill often fouls these slipsV and becomes broken up or distorts and breaks the spring fingers. The core catcher of the present 'invention embodies core gripping slips whose inward movement is definitely limited so that they cannot foul the core. l

Another object of this invention is'to provide av core catcher embodying core gripping slips and pivoted core gripping ldogs carried by a rigid body or ring so that there is little or no danger of their loss or failure.

l Another object of this invention is to provide a core catcher embodying slips pivotally mounted in the core catcher body in suche. manner that rotation of the core catcher with the drill during drilling operations tends to free the slips from the core in the event that they have prematurely engaged the core.

Another object of this invention is to provide a core catcher embodying pivoted or swingable slips mountedin the core catcher body in a. novel and particularly effective manner. v

Another object oi this invention is to provide a core catcher of the character mentioned embodying a fioating ring mounted'in the core drill forv free rotation and provided with an inclined surface against which the' pivoted slips bear for actuation against the core. The slips of the ,l core catcher bearing on a free floating ring' do not cause'or tend to cause the core catcher to rotate with the drill whereby the core catcher may remain nonrotatable, during thev rotary drilling to score or mutilate the core to aminimum extent.

Another object of this invention is to provide a core catcher that is operable to receive and retain a full sized unmutilated core.

Another object of this invention is to provide a core catcherl that is strong and long wearing and that does not embodyparts subject to failure or distortion through contact with the core.

The various objects. andA features of my invention will be fully understood from the following detailed description of a typical .preferred form and application of my invention, through- A popular form of 1936, serial No. 64,068

out which description reference is made to the accompanying drawings; in which:

, Fig. '1 is a side elevation of a core drill with a lower portion broken away to illustrate the core catcher of the present invention arranged therein. Fig. 2 is an enlarged plan elevation view of the core. catcher with a portion broken away to appear in horizontal cross section being a view taken substantially as indicated by line 2-'2 on Fig. 3. Fig. 3 is a side elevation of the core catcher with aportion broken away to appear in vertical cross section being aview taken substantially as indicated by line 3-3 on Fig.,2. Fig. 4 is a fragmentary plan view of the core catcher showing one of the slips in the actuated position. Fig. 5 is a fragmentary vertical detailed sectional view showing an actuated slip bearing on the oating ring. Fig. 6 is; an enlarged fragmentary vertical detailed sectional view taken substantially as indicated by line t--t on Fig. 2 and Fig. 7 is a fragmentary horizontal 'sectional view taken substantially as indicated by line I-Ji on Fig. 6.

The core catcher ofV the present invention is capable of embodiment in forms for use in various types and classes of -core barrels or core e drills. In the following detailed disclosure i will describe one typical form and application oi the invention, it being understood that the invention is not to be construed as limited or restricted to the specic form and details about to be described. W

The core drill illustrated in. the drawings comprises an outer barrel Iii whose upper end is adapted to be connected with a rotary drilling string. A' tubular connecting member or sub ii is threaded on the lower end of the outer barrel Il! and a bit head I2 is threaded to the lower end of the sub II. The bit head I2 is tubular being i receiving the core. Cutting means are provided on the head I2 for making an annularl cut in the earth formation. In the case illustrated in the drawings roller cutters I4 are rotatably supported .in pockets I5 in the lower end of the head I2 to make an annular cut in the earth formation and leave a core for reception in the opening I3. The sub II- is provided adjacent its lower end withan internal 'upwardly facing shoulder I6 and a sleeve I1 ts on this shoulder I t to extend upwardly in the sub. In practice the sleeve l'i may be weldedto the sub II` atv the shoulder I6. The sleeve I1 is spacedfrom the interior of the sub II leaving an annular passage I8 for the circulation fluid. Spaced or ported parts k3I9 project from the `interior of the sub I I to engage the sleeve I1 adjacent its upper end and operate to support and centralize the sleeve.

An -inner barrel 20 extends longitudinally through the outer barrel I0 to receiveA the core formed by the cutters I4.' A bearing member 2I is fixed to the lower end of the inner barrel 29 and has a shoulder 22 adapted to rotatably bear on the upper end of the sleeve- I1 to rotatably l0 support the inner barrel 20 in the outer barrel I 9. The bearing member 2| projects into 'the sleeve I1 and its lower end presents a downwardly facing shoulder 23 in the sleeve, The sleeve I1 has an upwardly facing internal shoulder 24 spaced some distance below the shoulder 23. The inner barrel is spaced ,from the interior of the outer barrel I 0 leaving an annular passage 25 for the downwardly flowing circulation uid. Ports 26 are provided in" the bearing member 2l 20 and communicate with the'lower end of the passage and the upper end of the passage I6. Ports 21 and 28 extend downwardly through the sub I I and the bit head I2 from the lower end of the passage I8 to the pockets I5 to carry the 25 circulation fluid to the pockets where it discharges against the lcutters I4.

The core catcher of the present invention includes, generally, a iioating ring 29 arranged in the sleeve i1 -between the shoulders 23 and 24, a 30 ring or body 30 extendingl through the ring 29, pivoted dogs 3| on the body 30, and pivoted slips 32 on the body 30 operableV by engagement with the ring 29 to grip a core extending through the tool.

The "ring 29 is provided in the sub sleeve I1 between the shoulders 23 and 24 and is freely rotatable therein whereby it may remain non-rotatable during rotation of the drill. 'I'he ring 29 forms a wedge element or actuating abutment for, the slips 32. The internal surface 33 of the ring 29 is inclined downwardly and inwardly, being shaped for engagement by the slips 32 as will be hereinafter described. The inclined surface 33 may extend substantially the entire length of the ring 29 as illustrated in the drawings. The abutment ring29 being positioned between the shoulders 23 and 24 is constrained to move vertically or longitudinally with the vouter barrel I0 and sub I I.

The body 3l! forms a support or carrier for the dogs 3l and-the gripping slips 32. The body 30 of the core catcher is in the nature of a tube or ring and is arranged axially or longitudinally in the sub sleeve I1. 'I'he body 30 may be of sub- 55 stantial length and may extend longitudinally through the ring 29. In accordance with the invention the body 30 is a iioatlng-element free to remain non-rotatable during the rotary drilling operations. The core 'catcher body 30 may be 60 integral, however, it has been found practical to form the body 39 in two sections, 34 and 35. The section 34 is the mainy or principal section of the body 39 and the section V35 isA a ring-like part telescoping over the lower portion of the section 65 34 and projecting downwardly from the lower end of the section 34. The opposing and engaging surfaces of the sections 34 and 35 are provided with annular opposing grooves registering to form anannular opening 36 which is concentric 70 with the longitudinal axis of the body 30. The

body sections 34 and 35 may be detachably connected by rivets 31 or the like, which may pass through the opening 36 as clearly shown in Fig. 2

of the drawings. The internal diameter of the body 30 is substantially the Same as the core reis moved upwardly to actuate the slips 32.

ceiving opening I3 of the head I2. A plurality of circumferentially spaced windows or openings 36 is provided in the wall of the body 30 to receive the dogs 3I.

The dogs 3I are provided to assist in gripping and retaining the core and act to resist movement of the body 30 relative to the core when the drill The dogs 3| are pivotally supported in the openings 38 on pins 39 whose end portions are carried in the annular opening 36. The end portions of the pins 39 may be flattened as shown in Fig. 2 of the drawings to cooperate with the walls of the opening 36 to prevent rotation and longitudinal movement of'the pins. The dogs 3I pivoted on the pins 39 are adapted to pivot downwardly and inwardly in the interior of the body 30 to bite into the core. The active ends or edges 40 of the dogs 3l are pointed or sharpened to readily cut into the core. If desired, the dogs 3| may be of diierent lengths as shown in the drawings. In the form of the invention disclosed some of the dogs 3| are relatively long to be capable of gripping and retaining soft under-sized cores, some of the dogs 3I are of medium length to dependably bite into medium hard cores, while certain of the dogs 3| are relatively short to dependably grip hard fullsized cores. Means are provided for urging the dogs 3i into cooperation with the core. Slots 4I are provided in the outer ends of the dogs 3I and torsional springs 42 are provided in the slots 4I and are wrapped about the pivot pins 39. The springs 42 bear against the body section 35 and the dogs 3I to urge the dogs downwardly and inwardly against the core.

The character, mounting and operation of the slips 3'2 are features of the invention. The slips 32 are carried by the core catcher body 30 above the dogs 3I and are operable through cooperation with the inclined surface 33 to tightly grip and retain the core. Openings 44 are provided in the wall of the body 30 to receive the slips 32. Ihe openings 44 are space'd above and in offset relation to the dog receiving openings 36. In the preferredconstruction the openings 44 are rectangular being elongated circumferentially of the body 30. The slips 32 are substantially rectangular members proportioned to it the'openings 44 with substantial clearance. The inner or active faces of the slips 32 are provided with wickers or teeth 45 to bite into and retain the core.

In accordance with the invention the slips 32 are supported to pivot' or swing about axes which are substantially parallel with the longitudinal axis of the core drill. A substantially vertical opening 46 is provided in the rear portion of each slip 32 relative to the direction of rotation of the drill. Pins 41 extend through the openings 46 and have their end portions carried in openings 48 in the body 30to pivotally support the slips 32. The slip carrying pins 41 are preferably stationary or fixed. In the structure shown in the drawings the upper portions of the pins 41 are threaded in the openings 48. The upper and lower sides of the slips 32 may have bearing bosses or lugs 49 bearing outwardly against the walls of counterbores 50 in the openings 48. The slips 32 mounted as just described are capable of swinging about substantially vertical axes between positions where they are substantially retracted in the openings 44 as shown in Fig. 7 to positions where they project into the body 30 as shown in Fig. 4 to grip the core.

The, openings 39 are substantially' rectangular and intersect the annular opening 36.

2,070,887 Each slip 32 has la surface 52 on its outer side for cooperating with the 'inclined surface 33 of the iioating ring 23.v The surfaces 52 .of the slips 32 are curved to conform to the surface 33 and' 5 are inclined downwardly and inwardly to evenly bear on the surface. Means are provided for yieldingly urging the slips 32 outwardly-to have.

cooperation with the surface 33 and to normally remain in their retractedpositions where they do not engage the core. Horizontal slots 53 are provided in the inner or rear ends of the slips 32 and intersect the ,openings 43. Torsional springs 4 are wrapped about the pins 41 in the slots 53 and bear on the slips 32 and the body 33 to urge the slips 52 cooperate with the surface 33. 'I'he'invention provides means for definitely limiting the inward' movement of the slips 32. Stop lugs 55 are provided on the outer or forward ends of the slips 32 and are adapted to cooperate with-recesses 53 in the body 33 to positively limit the inward swinging of the slips 3 2. 'This definite limiting of the inward travel of the slips 32 is important as it prevents the slips from fouling the core.

During operation the outer barrel I0 is connected with the rotary drilling string and is rotated and'fed downwardly in the well so. that the cutters Il cut into the earth formation to form the core for reception in the drill. C irculation uid is continuously pumpedV downwardly through the strip to iiow through the passages I 25 and I8 and the ports 21 and 23 and discharge against the cutters i4. The slips 32 are normally urged outwardly against the inclined surface 33 by the springs 54 while the dogs 3| are urged .inwardly to positions such as illustrated in the drawings. As the drill moves the core the dogs 3| engage the upper. end of the core as it4 enters the bodyf3ll.l 4This Vengagement of the dogs 3| with the core tends to hold the body 30 stationary relative to the rotating and downwardly moving drill. Accordingly, the engagement of the dogs 3| with the core tends to hold the body 30 stationary while the ring 29 moves downwardly with the drill. The resulting relative movement between the ring 23 and the slips 32' results in the full retraction of the slips under the action of the springs 5l. In this manner, the slips 32 are fully retracted before they reach the upper end of the cpre. The retracted slips 32 do not in any way interfere with the core and do notr mutilate or groove the core. The

engagement of the dogs 3| withy the core may be sufficient to hold the body 33 against rotation 55 with the drill so that the core is not subjected to aV cutting Aaction or scoring action by the core catcher. The innerbarrel 20 is operable to receive the core when it emerges through the core catcher. 60 When it becomes move the ,core the actuate the the\'dogs 3| with the core .holds or substantially holds the body 30 against upward movement with the drill so that the upward movement of the drill results in relative vertical movement between the surfaces 33 and 52. The surfaces 33 and 52 cooperate during' this relative vertical movement tof swing or pivot -the slips 32 inwardly into grip- 70 ping contact 'with the core. The slips.32 may be forced'inwardly' through the coo' ration,v of the surfaces 33 and 52 until they ob ain a firm hold A on the core. Upward movement'of, the drill alsof usually causes the dogs 3| to obtain nrmer 75 and deeper engagement' with the core.y Condesirable to recover Yor reoutwardly to have their surfaces downwardly over drill is moved upwardly to core catcher. The engagement of tinued upward movement of thedrill results in the breaking of the core-fromthe'earth forma-l tion. The slips 3 2 and the dogs 3| biting into the core support and retain the core for withdrawal from the well.

' II"he core catcher of the present invention is such that it cannot foul or destroy the core; The lugs 55 positively ,limit the inward movement of the slips 32 so that the slips cannot assume positions where they materially interfere with the passage 'of the core into the inner barrel. The ring 29'having the slip actuating surface 33 is free .to oat in the sleeve so that the engagement of the, slips 32 with the ring does notforce cr cause the core catcher bodyV 30 to turn with the drill. The parts are assembled and related so that there is a minimum amount of friction between them. The core catcherbody 30 may remain non-rotatable during the drilling and the dogs- 3| and the slips 32 have little or no ftendency to groove or cut into the core.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set,for'th, but wish to reserve to myself any. variations or, modifications that may-appear to those skilled in the art or fall within the scope of the following claims: i

Having described my invention, I claim:

'1. In a core drill having an inclined internal surface, the combination of, a body in the drillY and a member carried by the body to swing inwardly about an axis substantially parallel with the longitudinal axis. of the drill through coopera-4 tion with the inclined surface.

2. In a core drillhaving an inclined vinternal surface, the combination of, a body arranged in the drill for relative longitudinal movement, a core gripping member,- and means supporting the' member cn the body to swing about a substantially vertical axis through cooperation with said surface. y

3. In a core drill surface, the combination of, a body arranged in i the drill for relative longitudinal movement, a f core gripping slip on the body swingable inwardly about a substantially vertical axis through cooperation with sald surface, and means on the body having movement resisting cooperation with the core whereby vertical movement of the drillactuates the slip. 4. Inl a core drill having an inclined. internal surface, the combination of, a body arranged in the drill for relative vertical movement, a pivoted dcg on the body operable to engage a corel to resist movement of the body, and a core gripping slip. pivoted onthel body to swing about a subg stantially vertical axis and engaging said surface whereby the surface actuates the slip upon relai tive vertical movement between the drill and body in one direction. 5. A core catcher for a core drill comprising, a ring to be arranged in the drill for vertical movement therewith, the ring having an inclined surface, a body to be arranged in the drill for relative vertical movement, core gripping slips, and means pivotally supporting the pivotal movement about substantially vertical axes and to pivt inwardly through cooperation with the inclined surface upon relative. vertical movement between the drill land body.

6. A core catcher fora core drill comprising,

a ring to be arranged in the drill for vertical movement therewith, `the ring having Van -inslips on the body for having an inclined internal l a substantially vertical to turn about a substantially vertical axis and to have cooperation with the inclined surface, and yielding means holding the slip in cooperation with the said surface. f1.

7. A core catcher for a core drill comprising, a ring to be arranged in the drill for vertical movement therewith, the ring having an inclined surface, a bdy to be arranged in the drill' for relative vertical movement, a core gripping slip pivoted to the body to swing about a substantially vertical axis, yielding means holding the slip in cooperation with the said surface, and means for resisting vertical movement of the body whereby the slip is actuatedby vertical movement of the drill.

8. In a core drill having a barrel withspaced internal shoulders, the combination of, a ring arranged between the shoulders for free rotation and for vertical movement with the barrel, a oating body in the barrel, and a. pivoted core gripping slip pivoted on the body to swing inwardly about axis through cooperation with the ring.

9. In a coredrill having a barrel with spaced `internal shoulders, the combination of, a ring arranged between theshoulders for free rotation and for vertical movement with the barrel, the ring having an inclined surface, a shiftable and freely rotatable body in the barrel, and acore gripping slip pivoted on the body to swing about a substantially vertical with said inclined surface.

10. In a core drill having a barrel with spaced internal shoulders, the combination of, a ring arranged between the shoulders for free rotation and for'vertical movement with the barrel, the ring having an inclined surface, a body arranged inthe barrel for relative shifting and rotation,

means on the body cooperable with the core to -in the barrel for relative shifting resist movement ci the body, and a pivoted core gripping slip on the body actuated through cooperation with said inclined surface to swing about a substantially vertical axis.

11. In a core vdrill having a barrel with spaced internal shoulders, the combination of, a ring arranged between the shoulders for free rotation and for vertical movement with the barrel, the ring having an inclined surface, a body arranged and rotation, anda core gripping slip pivoted to the body for swinging movement about a substantially vertiaxis through cooperation( vcore gripping slip,

cal axis and having an inclined surface for cooperating with the inclined surface of the ring.

v12. A core catcher for use in a core drill comprising, an annular body for' arrangement in the drill, the body having an opening'in its wall, a core grippingA slip, and means plvotally supporting the slip on the body for swinging through the opening about an axis substantially parallel with the longitudinal axis of the body.

13. A core catcher for use in a core drill comprising, an annular body for arrangement in the drill, the body having a lower opening in its its wall and an upper opening in its wall, a core engaging dog pivoted in the lower opening, and a core gripping slip pivoted in the upper opening tc swing about an axis substantially parallel with the longitudinal axis of the body.

14. A core catcher for use in a core drill comprising, an annular body for arrangement in the drill, the body having a lower opening in its wall and an upperopening in its wall out of vertical alignment with the lower opening, a core engaging dog pivoted in the lower opening, and a core gripping slip pivoted in the upper opening to swing about an axis substantially parallel with the longitudinal axis of the body.

15. A core catcher for use in a core drill cornprising, an annular body for arrangement in the drill, the' body having a lower opening in its wall and an upper opening in its wall, a core engaging dog pivoted in the lower opening, a core gripping slip pivoted in Vthe upper opening to swing about an axis substantially parallel with the longitudinal axis of the body, means urging the slip outwardly, and a member movable vertically with the drill and having an inclinedsurface for operatively engaging the slip.

16. A core catcher for use in a core drill comprising, an annular body for arrangement in the drill, the body having an opening in its wall, a means plvotally supporting the slip on the body for swinging through the opening about a substantially vertical axis, and means limiting inward swinging of the slip.

17. A core catcher for use in a core drill comprising, an annular body'for arrangement in the drill, the body having an opening in its wall, a

core gripping slip, means plvotally supporting the slip on the body for swinging through the opening about a substantially vertical axis, and means limiting inward swinging of the slip, the last named means comprising, a lug on the slip for engaging the body.

GEORGE F. GRIMMELSMAN. 

